1. Field of the Invention
This invention relates generally to an improved water bed safety liner, and specifically to a water bed safety liner that includes a bottom liner integrally joined to a four sided foam perimeter support cushion that itself is wrapped in a plastic sheet to make the entire unit, including the perimeter support cushion, waterproof. The safety liner also includes a valve in the bottom liner for ease in drainage of the waterbed mattress bladder, a valve stabilizer to ensure complete drainage of the bladder, and a plurality of sheet grippers to provide for use with conventional contoured bed sheets. The safety liner includes hinge-like construction at each end allowing the unit to be folded into a compact unit for storage and shipping purposes.
2. Description of the Prior Art
Most conventional water beds include a hardwood frame, a sheet of plastic which is used as a safety liner and a large bladder, filled with water, that acts as the waterbed mattress which is mounted over the safety liner within the hardwood frame. It is desirable to emulate in a waterbed certain characteristics found in traditional bedding (padded spring mattresses and the like) such as sitting comfortably on the side of the bed for entry or egress and using conventional contoured bed sheets. The prior art shows a variety of devices which attempt to create in a waterbed having one or more of the attributes found in padded and spring bedding. One important aspect is the support provided by the perimeter frame around the water filled bladder. U.S. Pat. No. 4,703,531, issued to Bissett, Sept. 3, 1987 and U.S. Pat. No. 4,799,277, issued to Goodale, Jan. 24, 1989 deal with various types of padded peripheral rails. Some waterbed "mattresses" have been called "hybrid" and use a variety of foam rail configurations, an example of which is shown in U.S. Pat. No. 4,745,646, issued to Strobell, May 24, 1988. A reinforced wall, "soft-side" waterbed is shown in U.S. Pat. No. 4,771,491, issued to Fogel et al., Sept. 20, 1988. A waterbed with removable side cushions is shown in U.S. Pat. No. 4,637,082, issued to Moore et al., Jan. 20, 1987. U.S. Pat. No. 4,186,455 issued to Fox, Jr. et al. shows a composite waterbed mattress that uses some foam adjacent the hardwood frame in conjunction with other foam cushions to provide an outer peripheral surface for the mattress which is suitable for sitting. None of the references provide a safety liner that is integrally formed including a comfortable peripheral support for sitting that is also suitable for use with conventional contoured sheets.
Drainage of the bladder in a waterbed is a problem because the elevation of the hardwood frame side edges requires that the hose be brought from the bottom of the mattress up over the sides and then back down again requiring a syphon to completely empty the bladder. With the safety liner in accordance with the present invention, the bladder can be drained by gravity below the bladder support surface without the syphon-effect through the safety liner floor.
The present invention overcomes deficiencies in the prior art by providing a safety liner that includes a plastic sheet floor integrally constructed to a firm yet comfortable foam peripheral core wrapped in a plastic sheet that is supported on the hardwood frame. The foam peripheral support cushion is sized, shaped and positioned such that it is comfortable to sit on, making for easy entry and egress from the waterbed mattress. The safety liner encloses and contains the entire bladder of the waterbed (except the top surface) in a watertight enclosure. The configuration of the foam support cushion can also reduce the amount of hardwood frame required. Other advantages provided by the invention include a foam core cross sectional configuration that greatly aids in the use of conventional contoured sheets, a fold-up construction for storage and shipping, sheet grippers and a strategically located drain valve which permits the mattress bladder to be easily drained when necessary.
It is an object of this invention to provide an improved waterbed safety liner which provides for a soft edge bed having easy entry and egress while safely encompassing the water-filled bladder in a water impervious liner.
It is another object of this invention to provide an improved waterbed safety liner which can be compactly folded for storage and shipping purposes without sacrificing the watertight integrity of the safety liner.
It is another object of this invention to provide an improved waterbed safety liner that includes a drain valve and valve stabilizer for simplified hose draining of the water-filled bladder by gravity without the need for a syphon effect.
Yet still another object of this invention is to provide an improved waterbed safety liner that, through its configuration, allows for the use of conventional contoured sheets in a conventional manner while still incorporating sheet grippers to reduce hammocking effect.
Still another object of the invention is to provide an improved waterbed safety liner that safely contains water should the bladder develop a leak while greatly reducing the cost of construction and the amount of hardwood required for the frame.
In accordance with these and other objects which will be apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.